Really, really fast in the case of the privileged teenagers portrayed in the CW's delicious new drama series "Gossip Girl."

These underage private-school elitists living on Manhattan's Upper East Side dress in designer threads, are fond of martinis and champagne, can seemingly drink at any bar in New York (no fears of losing liquor licenses here, apparently) and trade witty bons mots as if they're members of the Algonquin Round Table.

And don't even get us started on their randy sex lives.

"Gossip Girl," from the teen-addled brain of Josh Schwartz, who served up the canceled "O.C.," carries on the legacy of that West Coast soap opera and perhaps turns it up a notch with both drama and sheer teen-soapy goodness. (It's all quite a startling contrast to those hard-working youngsters slaving away on "Kid Nation," which also debuts tonight on CBS.)

"Gossip Girl" is based on a popular series of young-adult novels by Cecily von Ziegesar about a mysterious blogger who keeps all the city's rich kids up on what's going on in a very vibrant social circuit. On the show, the blogger is never seen but only heard in a voice-over by Kristen Bell (she of the recently canceled "Veronica Mars").

Gossip Girl's topic du jour, at least in the pilot episode, involves the two top dogs in the high school hierarchy: gorgeous Serena van der Woodsen (Blake Lively, a clone of a young Ellen Barkin, right down to that smirk) and her beautiful BFF Blair Waldorf (Leighton Meester). Serena has just returned to New York after leaving abruptly a year earlier for a Connecticut boarding school, and the whole community is wondering: Why did she go in the first place and what's she doing back?

Blair, who felt dissed by Serena's abrupt departure, is cool to her returning "friend," and things are only going to get uglier when the reason for her leaving becomes apparent. "There's nothing Gossip Girl likes more than a good catfight." (Us, too, GG. Us, too.) "And this one has the makings of a classic," the blogger says in one of her many voice-overs.

Meanwhile, Chuck, one of the social scene's biggest players (superbly slimy Ed Westwick), knows why Serena fled town, and he'll surely exploit this information for his own good.

The show's other standout character is Dan (Penn Badgley), a middle-class outsider and overall nice guy who stumbles into the clique accidentally. Lucky Dan might soon be romantically linked to Serena, who, like, is so out of his league on many levels.

At times, it's overboard and maybe a bit giggle-inducing, like watching little kids play dress-up. But overboard is exactly where "Gossip Girl" wants to be -- and what viewers must embrace when taking the guilty plunge.